1. Field of the Invention
The present invention relates in general to a magnetic head for use in a hard disc drive (hereinafter, referred to as an HDD). More particularly, the invention relates to the construction of a magnetic head for use in the HDD for which the high recording density has been obtained, a bonding device which is suitably employed in the process of manufacturing the magnetic head, and a bonding method.
2. Related Background Art
In recent years, the recording density of HDDs has been rapidly increased, and the width of each of the tracks as the recording areas in the hard disc as the recording medium has become remarkably narrow combined with the miniaturization of the HDDS. For this reason, with the tracking of the magnetic head by only a voice coil motor which has been conventionally carried out, it becomes difficult to position accurately the magnetic head in this narrow track. Thus, there has been proposed the control of the tracking based on the piggy back system.
The conventional magnetic head comprises a core actually writing and reading the recorded information to and from the hard disc, and a suspension for supporting the core. On the other hand, the piggy back system is characterized in construction by providing a fine adjustment actuator between the core and the suspension (hereinafter, referred to as a gimbal). That is, the system of interest is such that the position of the magnetic head is moved to the neighborhood of the desired position of the tracking by the voice coil motor and then, the position of the core is corrected by the fine adjustment actuator, whereby the tracking of the high accuracy is carried out.
As for the construction of the magnetic head for use in the piggy back system, for example, there is one shown in FIG. 4 and FIG. 5. A magnetic head 1 includes a core 10, a gimbal 2 which extends in one direction to support the core 10 at one end thereof, and a fine adjustment actuator 30 which is arranged between the core 10 and the gimbal 2. The gimbal 2 is composed of a flexure 4 formed of an insulating flexible resin thin plate on which a conductor pattern for wiring is formed, a load beam 3 which is formed of a elastic metallic thin plate or the like to which the flexure 4 is adhered, and a base plate 7 which is firmly fixed to the base portion of the load beam 3 as the other end of the gimbal 2.
The head portion of the flexure 4 has an actuator attaching portion 5 which is not adhered to the head portion of the load beam 3, but is arranged so as to lie on the load beam 3 roughly in parallel therewith. The fine adjustment actuator 30 is firmly fixed to the actuator attaching portion 5, and the core 10 is fixed to the fine adjustment actuator 30 so as to be able to pivot in the extension direction of the gimbal 2.
A dimple (a projection portion for abutting from the back face the flexure 4) 6 which is formed integrally with the head portion of the load beam comes in contact with the back face of the actuator attaching portion 5, i.e., the back face of the flexure 4 (refer to FIG. 1). Normally, the fixing of the core 10 and the fine adjustment actuator 30 to the flexure 4 is carried out such that the pivotal center of the core 10 is aligned with the center of the dimple 6.
An element (not shown) including an electromagnetic conversion element and a magnetoelelctric conversion element, and electrodes 11 which are used to draw the electrical signal from that element to the outside are formed on one end face of the core 10. The electrodes 11 are electrically connected to end portions 8 of the electrical wiring provided in the flexure 4 (hereinafter, referred to as a substrate land) through wires 66 each made of Au or the like. In this connection, the flat surface in which the substrate lands 8 are formed and the flat surface on the core 10 in which the electrodes 11 are formed make an angle of about 90 degrees.
As for the method of connecting electrically the electrodes formed on the two flat surfaces making an angle of about 90 degrees as described above, there have been proposed the various methods such as the wire bonding method disclosed in Japanese Patent Application No. 10-56046 and No. 11-235785 by the present applicant, and the ball bonding method employing conductor balls disclosed in Japanese Patent Application Laid-open No. 9-283568 by the present applicant.
As described above, in the construction as well of the magnetic head employing the piggy back system, the electrodes 11 and the substrate lands 8 need to be electrically connected to each other through the wires 66. However, the fine adjustment actuator 30 is present between the core 10 and the flexure 4, and also the fixed distance is defined between the electrodes 11 and the substrate lands 8. Therefore, the ball bonding method disclosed in Japanese Patent Application Laid-open No. 9-283568 is difficult to be applied thereto.
In addition, in the above-mentioned wire bonding method, when bonding the wires 66 to the electrodes 11 and the substrate lands 8, the core 10 and the flexure 4 are clamped by a clamp mechanism to carry out the fixing therefor. However, the fine adjustment actuator 30 is in general weak against the force applied from the outside and hence is readily damaged. Since in the clamp mechanism in the conventional wire bonding method, the fine adjustment actuator 30 is loaded with the force for clamping, the method of interest can not be directly applied to the magnetic head employing the piggy back system.
In addition, while in the magnetic head employing the piggy back system, the core 10 is pivoted by the fine adjustment actuator 30, when each of the wires 66 is short, there may occur the case where the pivotal movement is limited by these wires 66. Therefore, in order to carry out smoothly and accurately that pivotal movement, each of the wires 66 needs to have the flexibility and the sufficient length. Further, against the bending which is applied to the wires 66 by the pivotal movement operation, each of the wires 66 needs also to have the sufficient durability.
In the light of the foregoing, the present invention has been made in order to solve the above-mentioned problems associated with the prior art, and it is therefore an object of the present invention to provide a method and device for, without carrying out the clamp for a fine adjustment actuator, connecting electrically electrodes and substrate lands to each other while maintaining the flexibility, and a magnetic head having the construction which can cope with the method and device.
In order to attain the above-mentioned object, according to the present invention, there is provided a magnetic head having a flexure having an electrical wiring formed therein, a fine adjustment actuator fixed to the flexure, and a core which is fixed to the fine adjustment actuator and also is electrically connected to the electrical wiring to be driven for the flexure by the fine adjustment actuator, characterized in that the core has a projection portion which is projected outwardly from the fine adjustment actuator when viewed from the flexure to face the flexure, and a hole which is penetrated to the rear face in the position roughly facing the projection portion is formed in the flexure.
In addition, in the above-mentioned magnetic head, it is preferable that the projection portion is projected in the direction in which the end portion of the electrical wiring is formed on the flexure, and that the through hole is formed between the end portion of the electrode wiring and the end portion of the lower face of the fine adjustment actuator. Also, it is preferable that the wire through which the core and the end portion of the electrical wiring are electrically connected to each other has the flexibility as well as the flexure.
In addition, in order to attain the above-mentioned object, according to the present invention, there is provided a device for manufacturing a magnetic head, for use in a magnetic head having a flexure having an electrical wiring formed therein, a fine adjustment actuator fixed to the flexure, and a core which is fixed to the fine adjustment actuator and is driven for the flexure by the fine adjustment actuator, a device for wire-bonding an electrode formed in the core and the end portion of the electrical wiring to each other, the device including a work fixing block including a first support surface to which the rear face of the formation part of the end portion of the electrical wiring in the flexure, and the vicinity thereof are both fixed and a second support surface for supporting the core, and a work clamp pin for clamping together with the second support surface the core to fix it.
In addition, in the above-mentioned device, it is preferable that the core has a projection portion which is projected outwardly from the fine adjustment actuator when viewed from the flexure to face the flexure, and that a hole which is penetrated through the flexure to the rear face in the position roughly facing the projection portion is formed in the flexure, and the second support surface is provided through the hole portion to support the core.
Further, in the above-mentioned device, it is preferable that the wire bonding is carried out with the core and flexure held by the work fixing block and the work clamp pin, and also is carried out such that after completion of the bonding to one of the core and the end portion of the electrical wiring, the core and the flexure are pivoted by about 90 degrees while being fixed to carry out the bonding to the other. Furthermore, the wire through which the core and the end portion of the electrical wiring are electrically connected to each other is preferably connected in the state of being bent, and the bonding of the wire to the core and the end portion of the electrical wiring is preferably carried out by using the ultrasonic wave.
In addition, according to the present invention, as a device for manufacturing electronic components having the same object, there is provided a device for wire-bonding the end portion of the electrical wiring and the electronic component to each other, for use in an electronic device including a substrate having an electrical wiring, a driving device which is fixed to the substrate in the position different from that of the formation of the electrical wiring on the substrate, and an electronic component which is fixed to the driving device to be driven by the driving device, the device including a work fixing block having a first support surface to which the rear face of the formation part of the electrical wiring in the substrate, and the vicinity thereof are both fixed and a second support surface for supporting only the electronic component, and a work clamp pin for clamping together with the second support surface the electronic component to fix it.
Furthermore, as the above-mentioned device, it is preferable that the electronic component has a projection portion which is projected outwardly from the driving device when viewed from the substrate to face the substrate, and a hole which is penetrated through the substrate to the rear face in the position roughly facing the projection portion is formed in the substrate, and that the second support surface is provided through the hole portion to support the electronic component.
In addition, in order to attain the above-mentioned object, according to the present invention, there is provided a method of wire-bonding an electrode formed in the core and the end portion of the electrical wiring to each other, for use in a magnetic head having a flexure having an electrical wiring formed therein, a fine adjustment actuator fixed to the flexure, and a core fixed to the fine adjustment actuator to be driven for the flexure by the fine adjustment actuator, the method including the steps of: fixing the rear face of the formation part of the end portion of the electrical wiring in the flexure and the vicinity thereof by the first support surface; clamping the core by the second support surface and the work clamp pin to fix the flexure, the fine adjustment actuator and the core integrally with one another; bonding the wire end portion to one of the electrode formed in the core and the end portion of the electrical wiring on the flexure; and rotating the flexure, the fine adjustment actuator and the core integrally with one another by about 90 degrees to bond the wire to the other of the electrode formed in the core and the end portion of the electrical wiring on the flexure.
Further, as the above-mentioned method, it is preferable that the core has a projection portion which is projected outwardly from the fine adjustment actuator when viewed from the flexure to face the flexure, and a hole which is penetrated through the flexure to the rear face in the position roughly facing the projection portion is formed in the flexure, and that the second support surface is provided through the hole portion to support the core. In addition, the wire through which the core and the end portion of the electrical wiring are electrically connected to each other is preferably connected in the state of being bent, and the bonding of the wire to the core and the end portion of the electrical wiring is preferably carried out by using the ultrasonic wave.